1. Field of the Invention
Embodiments of the present invention relate to telemetry systems and, in particular, to remote controlled telemetry systems with variable parameters and to telemetry systems implanted in human bodies in which the bandwidth and Q, among other parameters, are variable.
2. Description of Related Art
The use of implantable devices to remedy medical conditions is becoming increasingly frequent as the size and cost of such devices shrink. Many people with medical conditions who, in the past, were burdened with the prospect of remaining close to an analytical or treatment device have newfound freedom with implantable devices that allow them to receive the analysis and/or treatment they need from the implantable device.
For example, in the past, many diabetics who have needed blood glucose analysis on a daily basis or even multiple times during a day and who have required insulin injections in response to the analysis have been limited in their freedom of movement due to the requirement of remaining close to the analysis and treatment equipment. Implantable devices have changed much of that. Now, because blood glucose sensors and insulin infusion pumps have reached a state where they may be implanted into the body of a diabetic, diabetics are able to maintain a normal lifestyle while still obtaining the necessary analysis and treatment needed to combat their diabetes, without concern that a blood glucose analyzing device or insulin and needles are close at hand.
While implantable medical devices have improved the lives of many people with medical conditions, the devices themselves have still imposed certain requirements on the people who use them. For example, many implantable devices operate in conjunction with an external controller. Typically, data, software or other information is transmitted and/or received between the controller and the implantable device. The transmission of information between a controller and an implantable device imposes certain requirements on the person with the implantable device. For example, because the data transmission and reception range of the implantable device is necessarily limited, primarily due to power limitations and safety concerns having to due with data transmission from within a human body, the person with the implantable device must remain in relatively close proximity to the controller, within inches, in some circumstances.
Moreover, because data transmission rates of implantable devices are limited, also due to power limitations, the transmission of large amounts of data can take an exceedingly long time. For example, if historical data is transferred from an implantable device to an external controller for review or analysis by a medical professional, the historical data may encompass up to 100 kybtes of data or more. Likewise, if new software for an implantable device is to be downloaded from a controller to the implantable device, possibly as a result of the analysis of the historical data, the new software may encompass tens of kbytes to hundreds of kbytes or more. The transmission and reception of data, software or other information encompassing tens of kbytes to hundreds of kbytes and more can impose inconvenient restrictions on the freedom of the person with the implantable device, restrictions that the implantable device was supposed to remedy.
Generally, in telemetry circuitry, data transmission range and data transmission rate have been at odds with each other. In telemetry applications where it is desirable that data transmission range be maximized, such as in an implantable device that is transmitting real time sensor data, for example, data transmission rate has been minimized. Conversely, in telemetry applications where it is desirable that data transmission rate be maximized, such as in an implantable device that is transmitting or receiving large amounts of data, for example, data transmission range has been minimized. In the past, telemetry circuit designers have been forced to decide on whether to design the telemetry circuit for maximum data transmission rate or maximum data transmission range. Alternatively, in the past, telemetry circuit designers have compromised and have tried to find a balance between data transmission rate and data transmission range, maximizing neither.
What is needed is telemetry circuitry that is programmable, i.e., programmable so that data transmission or reception range is maximized for those applications that require maximum data transmission or reception range and so that data transmission range is maximized for those applications that require maximum data transmission range. Embodiments of the present invention provide such programmable telemetry circuitry.